Yes, if you are a runner with metabolic restraints, adding cycling to your training can be helpful. Cycling, in this case, can help increase the overall metabolic elasticity of your body which enhances your abilities to eat healthier in endurance activities. Since cycling is a non weight bearing sport it enables quicker recovery, and easy cycling workouts can be beneficial for training your body to utilize energy efficiently. For instance, even if your metabolic capacity leaves your running pace perpetually monotonous, cycling can help you include an easier form of endurance training.